Hafler DH-500: should I?

[viivo]

I was looking around a favorite local used electronics store and saw this big boy. Price is $240, it looks great on the outside and was told I could return it if there are any problems. The Hafler pre-amp was sitting beside it.

The question is do I really want them? I've been wanting to put together a nice 2.0 system but not sure I can afford speakers that would do it justice.

So would it be worth it, even if it sits until I can find the right speakers? Any speaker recommendations?

Thanks.

edit: sorry, should have included more info. The DH-500 is a stereo amp that weighs 50 pounds and is said to be conservatively rated at 225w per channel @ 8ohms. I had never heard anything about it, but after searching it seems they are popular for modding and will basically last forever with a little maintenance.

 

[NutBucket]

It's definitely a nice piece...and you can never have too much power. Hope on a site like Audiokarma and find a good tech in your area to go through it.

And depending on the price, pick up the pre-amp too.

 

[joetekubi]

While I dreamed of a DH-500 for many years, I recently found out from a top Hafler tech that he can't repair any 500s - the output Mosfet power transistors are unobtainable. So buy it if you'd like, but be warned. If you can get the preamp at a reasonable price (< $75 or so) and it's in good shape, that should be good.

 

[sdifox]

While I dreamed of a DH-500 for many years, I recently found out from a top Hafler tech that he can't repair any 500s - the output Mosfet power transistors are unobtainable. So buy it if you'd like, but be warned. If you can get the preamp at a reasonable price (< $75 or so) and it's in good shape, that should be good.

wut? Not even equivalents? I can understand if you say you have to replace all of them to an alternate but not finding a compatible mosfet is ludicrous.

 

[NutBucket]

But there's no guarantee that comparable MOSFETS will achieve the same sound....

 

[sdifox]

But there's no guarantee that comparable MOSFETS will achieve the same sound....

but we are talking last resort kind of repair.

 

[NutBucket]

True. And truth be told, those output stage parts are pretty tough. If the rest of the unit is well kept there really isn't a large risk of blowing them.

 

[joetekubi]

I may have remembered wrong - I can't find the thread about the DH-500 output mosfets.
Here is advice from a Hafler guru:

The DH-500 is noted as a powerhouse with low $$ cost per watt. Its recent version uses the P-19C circuit cards that feed 6 MOSFETs per channel, and has rail voltages of ±90 VDC. This is the same circuit card used in the DH-220/P-225/230.

The DH-500 is more complicated than the DH220 or its professional version, the P-230. It has an output monitoring circuit that protects speakers from excessive DC offset should it occur because of some sudden fault condition. It also provides a time delay to the relay that switches output to the speakers, thus eliminating dangerous transients (thumps) at turn-on. It also has a thermal controlled 2-speed fan to cool the "wind tunnel" on which the output MOSFETs are mounted.

Because it has more "moving parts" than its younger brothers (DH-220/P-225/P-230) there is a greater possibility of something going wrong. For example, its 45 VDC field coil relay sometimes fails and replacements are almost non-existant.
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On that basis, I'd (now) suggest buying the 500.

BTW, everyone that has a Hafler power amp loves it.
Apologies for any mis-information.

 

[Kaifill]

I have owned a Hafler DH500 and the Hafler DH110 preamp since August 23rd 1984 and they're still going strong in 2016. Almost 32 years of trouble free service. It's the best investment since my Nakamichi LX-3 from 1983. Denon DR-44HX since 1985. All of these pieces are still going strong in 2016. If you ever come across any of them that are in good condition, they're worth it. As long as you don't abuse them, they will last a lifetime.